This application claims the priority of German patent document 196 39 765.0, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a bicycle frame, and more particularly to a bicycle frame including a steering receiving member, a saddle receiving member, a top member, and an inclined member.
From D'Aluisio, U.S. Pat. No. 5,201,537, a bicycle frame is known which, on the one hand, forms an open triangle between a forward top tube, a section of an inclined tube and a section of a rearward top tube and, on the other hand, forms another triangle between the top tube, a saddle tube and an inclined tube. A forward fork for a front wheel is linked to a steering tube of the frame and a rearward rocker or fork for a rear wheel is linked to the saddle tube and an inclined tube.
It is an object of the invention to provide a bicycle frame which comprises a base frame from which variably designed bicycle frames can be produced and the bicycle frame can be assembled in a simple manner from a few frame tubes and is to be particularly suitable for a fully shock-mounted bicycle.
This and other objects have been achieved according to the present invention by providing a bicycle frame, comprising: a steering receiving member; a saddle receiving member; a top member comprising a forward section which is connected to the steering receiving member and a rearward section which is connected to the saddle receiving member; and an inclined member extending between said top member and a pedal bearing unit, a junction existing between the forward and rearward sections and the inclined member in a horizontal plane located below each of a connection of the rearward section to the saddle receiving member and a connection of the forward section to the steering receiving member.
This and other objects have been achieved according to the present invention by providing a bicycle frame, comprising: a steering receiving member; a saddle receiving member; a top member comprising a forward section which is connected to the steering receiving member and a rearward section which is connected to the saddle receiving member; an inclined member extending between said top member and a pedal bearing unit; and at least one junction plate extending between the inclined member and the top member proximate a junction between the forward section and the rearward section.
This and other objects have been achieved according to the present invention by providing a method of manufacturing a bicycle frame having a steering receiving member, a saddle receiving member, a top member comprising a forward section and a rearward section and an inclined member, said method comprising the steps of: connecting said forward section of the top member to the steering receiving member; connecting said rearward section of the top member to the saddle receiving member; arranging said inclined member to extend between said top member and a pedal bearing unit; and arranging and interconnecting said forward section, said rearward section and said inclined member such that a junction is formed therebetween in a horizontal plane located below each of a connection of the rearward section to the saddle receiving member and a connection of the forward section to the steering receiving member.
Advantages achieved by the present invention are that the frame consisting of several assembled tubes, on the one hand, has a basic stability as well as a dynamic stability during compression operations. Thus, for example, the top tube is formed of a forward tube section, which is part of an inclined tube, and of a saddle tube section. A connection of the tubes in a junction close to a support bearing for a shock absorber or spring damper unit results in a stable support base for the rear swing unit which can be swivelled about a pivot in the area of the chain wheel (sprocket) in the pedal bearing.
The tube sections of the top tube are arranged angularly with respect to one another which results in a favorable entry section with a low-lying junction which is situated below the connection points on the saddle receiving tube and on the steering tube in order to enable easier mounting by a rider.
The constructions of a frame preferably have a saddle tube which projects toward the rear from the inclined tube and which in various constructions is reinforced in the area of the junction by way of metal plates or the like. The saddle tube section or the saddle tube receiving section can also be reinforced by means of a downwardly directed strut or fork which is supported on the inclined strut and which between one another accommodate the shock absorber unit or has a space for guiding through the shock absorber unit.
So that a stability of the frame is ensured despite a filigree linking of the saddle tube section to the inclined tube, reinforcements are provided either on the underside of the saddle tube section at least along a partial length or are arranged additionally in the junction on the top side of the meeting tubes of the saddle tube and of the forward tube section of the top tube.
According to another construction of the frame according to the invention, the tube sections of the top tube form a Y-shaped frame with the diagonal strut. As a result, a stable connection is achieved in that the two tube sections of the top tube in the bent area are supported by the inclined tube. This inclined tube directly its face meets the connection points of the two tube sections. The three tubes can be connected with one another via a welded connection. The forming junction is situated approximately in the center between the front wheel and the rear wheel.
So that an optimized connection can be achieved in the junction of the three tubes with respect to the length of the weld seams, the tube ends virtually overlap such that relatively long weld seams are formed and therefore also connections and supporting surfaces with respect to one another.
An additional support between the saddle tube section and the inclined tube takes place by means of an interposed connection console which simultaneously forms a support bearing for the shock absorber. Furthermore, additional reinforcing metal plates may be provided below the tube, for example, in the tube center plane.
According to a further development of the invention, the frame has a sheet metal or casting support with respect to the inclined tube in the junction of the tube section of the saddle tube and of the forward top tube. This support may be perforated or be provided with recesses having geometrical shapes, in which case the support simultaneously forms a bearing for the shock absorber.
Because of the frame parts which form a kit and have the same connection points, the swing unit can be inserted into any frame according to the constructions.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.